Olfactory sensitivity exhibits daily fluctuations. Several studies have suggested that the olfactory system in insects is modulated by both biogenic amines and neuropeptides. However, molecular and neural mechanisms underlying olfactory modulation in the periphery remain unclear since neuronal circuits regulating olfactory sensitivity have not been identified. Here, we investigated the structure and function of these signaling pathways in the peripheral olfactory system of the American cockroach, Periplaneta americana, utilizing in situ hybridization, qRT-PCR, and electrophysiological approaches. We showed that tachykinin was co-localized with the octopamine receptor in antennal neurons located near the antennal nerves. In addition, the tachykinin receptor was found to be expressed in most of the olfactory receptor neurons in antennae. Functionally, the effects direct injection of tachykinin peptides, dsRNAs of tachykinin, tachykinin receptors, and octopamine receptors provided further support for the view that both octopamine and tachykinin modulate olfactory sensitivity. Taken together, these findings demonstrated that octopamine and tachykinin in antennal neurons are olfactory regulators in the periphery. We propose here the hypothesis that octopamine released from neurons in the brain regulates the release of tachykinin from the octopamine receptor neurons in antennae, which in turn modulates the olfactory sensitivity of olfactory receptor neurons, which house tachykinin receptors.

선충절대기생세균(Pasteuria penetrans)이 감염되어 있는 온실토양을 이용하여 세균의 내생포자가 땅콩뿌리혹선충(Meloidogyne arenaria) 유충 표면에 부착하는데 대한 온도의 영향에 대해 시험하였다. 갓 부화된 뿌리혹선충 2령충(J2)을 페트리디쉬 내의 토양에 접종한 후 20℃, 25℃, 30℃, 35℃에서 7일간 처리하였다. 모든 온도에서 내생포자의 J2 부착률은 모두 100%로 나타났으나 J2당 내생포자 부착수는 25℃에서 28.3개로 가장 많았으며 30℃, 20℃ 및 35℃에서 각각 J2 당 20.2, 18.6 및 13.6개로 낮아졌다. J2를 접종하기 전에 세균이 있는 토양을 온도 별로 10일간 전처리하였을 때 내생포자 부착률은 실온에서의 60%에 비해 -30℃, 4℃, 40℃, 50℃ 및 100℃에서 각각 25.0, 31.7, 8.3, 5.0 및 0%로 현저하게 낮아졌다. J2 당 내생포자 부착수도 실온에서의 5.3개에 비해 -30℃, 4℃, 40℃, 50℃ 및 100℃에서 각각 3.5, 4.3, 1, 1, 0개로 적었다. P. penetrans 세균의 내생포자를 뿌리혹선충 종별로 J2에 부착 시험한 결과 땅콩뿌리혹선충에서는 100%였으나 당근뿌리혹선충(M. hapla)과 고구마뿌리혹선충(M. incognita)에서는 모두 0%로 본 균주는 뿌리혹선충 종에 대해 기주선호성을 가진 것으로 나타났다.

One of the overlooked points in mosquito blood feeding research is a final step before blood feeding such as finding a best position of blood feeding site and blood vessels underneath. How mosquitoes detect blood vessels especially using chemosensory organs prior to a final stage of blood feeding is totally unknown. Here we provide the anatomical and chemosensory evidence that a piecing structure of the mouthpart of the mosquitoes is an essential apparatus for the penultimate stage in blood feeding in mosquitoes. Indeed, mosquito mouthparts possesses a set of olfactory receptor neurons in sensory hairs, which are sensitive to volatile compounds present in host blood. Furthermore, the inhibition of gene expression of these odorant receptors delayed blood feeding of the mosquito from host animals. Taken together, these results identify that chemosensory perception in mouthpart is involved in mosquito blood feeding behaviors, which in turn allows mosquito to locate a feeding site more precisely.

The perilla leaf pyralid moth, Pyrausta panopealis Walker (Lepidoptera: Pyralidae), is a serious pest damaging to leaf perilla. In order to establish the life parameters of P. panopealis for eventual purpose of control, the developmental span of each stage were investigated under five temperature regimes (20℃ ~ 3 0℃). In addition, the larvicial efficacy of several on-the-market environment-friendly agricultural materials (EFAMs) was tested. The width of head capsule at each larval stage measured to be the mean of 0.21, 0.32, 0.47, 0.64, and 0.98 mm, respectively. The larval period of P. panopealis was longest at 20ºC as 27.0 days and shortened as temperature goes up to 30ºC as 11.3 days. Survivorship of the larval P. panopealis was the highest at 30ºC as 80%, whereas that of other temperatures ranged from 40% (20ºC) to 62.5% (27.5ºC), indicating that the P. panopealis appears to favor higher temperature. In addition to larval period, the duration of egg, prepupa, and pupa stages also shortened as temperature goes up, whereas the duration of adult stage increased as temperature goes up: from 4.1 days at 20 ºC to 6.1 days at 30ºC. After the perilla leaf pyralid moths were successfully stabilized in indoor environment the larvicidal efficacy of the ten EFAMs that were previously selected from the result of other moth species was tested aimed at 4th instar larvae for 48 hrs. Seven of the ten tested showed more than 90% of mortality within 12 hrs and reached nearly up to 100% within 24 hrs, but the remaining three showed less than ~70%.

배추좀나방과 담배거세미나방 유충에 대한 30종 한방 식물체 메탄올 조추출몰의 살충활성 및 섭식 저해활성을 잎침지법을 이용하여 5,000ppm으로 검정하였다. 황련의 추출물은배추좀나방에 대해 살충작용을 보였다. 길경, 사삼, 세신, 오배자 및 자초의 추출물은 배추좀나방 유충에 대해, 목통 및 속새의 추출물은 담배거세미나방 유충에 대한 강한 섭식저해활성을 보였으나, 오배자와 황련의 추출물은 이들 나비목 유충 모두에 강한 섭식저해활성을 나타내었다.